* Enable or disable read state based on group attribute
* When read state needs to be published, the minimum unread count is calculated in the topic query. This way, we can know if someone reads the last post
* The option can be enabled/disabled from the UI
* The read indicator will live-updated using message bus
* Show read indicator on every post
* The read indicator now shows read count and can be expanded to see user avatars
* Read count gets updated everytime someone reads a message
* Simplify topic-list read indicator logic
* Unsubscribe from message bus on willDestroyElement, removed unnecesarry values from post-menu, and added a comment to explain where does minimum_unread_count comes from
